Kemp had an arthroscopic procedure on his left (non-throwing) shoulder on a torn labrum and a frayed rotator cuff. Afterward, doctors admitted the damage was more extensive than originally believed but they projected Kemp would be ready by opening day of the 2013 season.

Kemp tweeted on New Year's Day that he had reached am important milestone in the rehab process: "2day was a big step! The docs finally let me do an upper body workout. Spring Training right around the corner. Time 2 get this cardio!"

Kemp, 28, was injured when he crashed into the outfield wall at Coors Field on Aug. 27, though he played through the pain the rest of the season. Also limited by a hamstring injury in 2012, Kemp hit .303/.367/.538 with 23 homers, 69 RBIs and nine stolen bases.

"Matty was very open to me about how he felt, and right from the time he got hurt, he was never comfortable," his agent, Dave Stewart, told the Dodgers' website. "There were periods when it wasn't as painful, but he was never comfortable swinging the bat after he ran into the wall. But he kept playing because he wanted to be there for the team. With a possible playoff spot, he didn't want to sit. Nothing anybody could say or do could make him take time off."

Stewart added that he won't guarantee Kemp will be ready for opening day, but he said the center fielder is pain-free with spring training about a month away.

An All-Star in 2011 and 2012, Kemp finished second in the NL MVP voting in 2011, when he also won his second Gold Glove.